1. Field of the Invention
The invention relates to a liquid crystal display and an electronic device, and more particularly to a liquid crystal display and an electronic device with a touch function.
2. Description of the Related Art
Personal computers, mobile phones, and mobile information terminal apparatuses are commonly used information devices. In an information device, a touch panel device may be utilized. Thus, an object, such as a finger or a stylus pen, is utilized to input information or issue commands when a liquid crystal display displays information and comprises a touch function. Conventional methods are disclosed in Japanese Patents 07-302168 and 07-334289.
To achieve the touch function, a touch panel is combined with a liquid crystal display. However, transmittance, reflectance, or contrast ration of the liquid crystal display comprising the touch panel is reduced. Thus, display effect of the liquid crystal display is reduced.
Accordingly, a photo sensor within each pixel of a liquid crystal display to form a photo sensor array has been disclosed. The photo sensor array is capable of detecting light variations. When an object touches the liquid crystal display, the touched position can be determined according to the detection result.
However, transmittance, reflectance, or contrast ration of the liquid crystal display utilizing the photo sensor array is also reduced. Thus, display effect of the liquid crystal display is reduced. Further, an external encoder is required to analyze the signal provided by the photo sensor array. Thus, cost is increased and the structure of the liquid crystal display is made more complex. Additionally, the capacitor sensors are easily affected by external noise.